Wireless power receiving device, wireless power transmitting device and power calibration method using the same

Abstract

The wireless power transmission device according to an embodiment of the present specification corresponds to a wireless power transmission device for wireless power transmission to a wireless power receiving device. After the negotiation phase, the wireless power transmission device: receives a first reception power packet from the wireless power receiving device, the first reception power packet including an estimated reception power value indicating a first calibration data point; sends an ACK for the first reception power packet; receives a second reception power packet from the wireless power receiving device, the second reception power packet including an estimated reception power value indicating a second calibration data point; sends an ACK for the second reception power packet; receives a new second reception power packet from the wireless power receiving device, the new second reception power packet including an estimated reception power value indicating a third calibration data point; sends an ACK for the new second reception power packet; and configures a power calibration curve by using the first reception power packet, the second reception power packet, and the new second reception power packet.

Description

Technical Field

[0001] The present disclosure relates to a wireless power transmission device, a wireless power reception device that receives wireless power from the wireless power transmission device, and a method for calibrating power. Background Art

[0002] Wireless power transmission (or transmission) technology corresponds to a technology that can wirelessly transmit (or transmit) power between a power source and an electronic device. For example, by allowing the battery of a wireless device such as a smart phone or a tablet PC to be recharged by simply loading the wireless device on a wireless charging pad, the wireless power transmission technology can provide more outstanding mobility, convenience, and safety than a traditional wired charging environment using a wired charging connector. In addition to wireless charging of wireless devices, wireless power transmission technology is attracting attention as a replacement for traditional wired power transmission environments in various fields such as electric vehicles, Bluetooth headsets, 3D glasses, various wearable devices, household (or home) appliances, furniture, underground facilities, buildings, medical equipment, robots, entertainment, etc.

[0003] The wireless power transmission (or transmission) method is also called a non-contact power transmission method, a contactless power transmission method, or a wireless charging method. The wireless power transmission system may be configured with a wireless power transmitter that supplies power by using the wireless power transmission method and a wireless power receiver that receives the power supplied by the wireless power transmitter and supplies the received power to a receiver such as a battery unit.

[0004] Wireless power transmission technology includes various methods, for example, a method of transmitting power by using magnetic coupling, a method of transmitting power by using radio frequency (RF), a method of transmitting power by using microwaves, and a method of transmitting power by using ultrasound (or ultrasonic waves). The method based on magnetic coupling is classified into a magnetic induction method and a magnetic resonance method. The magnetic induction method corresponds to a method of transmitting power by using a current induced by a magnetic field generated from a coil battery cell of a transmitter to a coil of a receiver according to electromagnetic coupling between a transmitting coil and a receiving coil. The magnetic resonance method is similar to the magnetic induction method in terms of the use of a magnetic field. However, the difference between the magnetic resonance method and the magnetic induction method is that energy is transmitted due to the accumulation of a magnetic field (caused by the generated resonance) on both the transmitting end and the receiving end. Summary of the invention

[0005] Technical issues

[0006] The technical purpose of the present disclosure is to provide a wireless power transmission device, a wireless power reception device, and a method for calibrating power using the devices, which are capable of more accurately detecting foreign matter between the wireless power transmission device and the wireless power reception device.

[0007] The technical objectives to be achieved by the present disclosure are not limited to the above-mentioned technical objectives, and according to the following description, other technical objectives not described above will be clearly understood by ordinary technicians in the field to which the present disclosure belongs.

[0008] Technical Solution

[0009] In order to solve the above problems, according to one embodiment of the present disclosure, the wireless power transmitting device is a wireless power transmitting device that transmits wireless power to a wireless power receiving device; and after the negotiation stage, receives a first receive power packet including an estimated receive power value for a first calibration data point from the wireless power receiving device, sends ACK in response to the first receive power packet, receives a second receive power packet including an estimated receive power value for a second calibration data point from the wireless power receiving device, sends ACK in response to the second receive power packet, receives a new second receive power packet including an estimated receive power value for a third calibration data point from the wireless power receiving device, sends ACK in response to the new second receive power packet, and constructs a power calibration curve based on the first receive power packet, the second receive power packet and the new second receive power packet.

[0010] In order to solve the above problems, according to one embodiment of the present disclosure, a wireless power receiving device is a wireless power receiving device that receives wireless power from a wireless power transmitting device; and after a negotiation phase, a first receiving power packet including an estimated receiving power value for a first calibration data point is sent to the wireless power transmitting device, an ACK in response to the first receiving power packet is received from the wireless power transmitting device, a second receiving power packet including an estimated receiving power value for a second calibration data point is sent to the wireless power transmitting device, an ACK in response to the second receiving power packet is received from the wireless power transmitting device, a new second receiving power packet including an estimated receiving power value for a third calibration data point is sent to the wireless power transmitting device, and an ACK in response to the new second receiving power packet is received from the wireless power transmitting device.

[0011] In order to solve the above problems, according to one embodiment of the present disclosure, a wireless power receiving device is a wireless power receiving device that receives wireless power from a wireless power transmitting device; and after a negotiation phase, a first receiving power packet including an estimated receiving power value for a first calibration data point is sent to the wireless power transmitting device, an ACK in response to the first receiving power packet is received from the wireless power transmitting device, a second receiving power packet including an estimated receiving power value for a second calibration data point is sent to the wireless power transmitting device, an ACK in response to the second receiving power packet is received from the wireless power transmitting device, and based on a change in a target operating point, a new second receiving power packet including an estimated receiving power value for a third calibration data point is sent to the wireless power transmitting device or a new first receiving power packet including an estimated receiving power value for a new first calibration data point and a new second receiving power packet including an estimated receiving power value indicating a new second calibration data point are sent to the wireless power transmitting device.

[0012] Other details of the disclosure are included in the detailed description and drawings.

[0013] Beneficial Effects

[0014] According to the present disclosure, foreign matter between a wireless power transmission device and a wireless power reception device can be detected more accurately.

[0015] The effects according to the present disclosure are not limited to the above exemplary contents, and more various effects are included in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a block diagram of a wireless power system (10) according to an exemplary embodiment of the present disclosure.

[0017] Figure 2 is a block diagram of a wireless power system (10) according to another exemplary embodiment of the present disclosure.

[0018] Figure 3a Exemplary embodiments of various electronic devices employing wireless power transfer systems are shown.

[0019] Figure 3b An example of WPC NDEF in a wireless power transfer system is shown.

[0020] Figure 4 is a block diagram of a wireless power transmission system according to another exemplary embodiment of the present disclosure.

[0021] Figure 5 It is a state transition diagram used to describe the wireless power transfer process.

[0022] Figure 6A power control method according to an exemplary embodiment of the present disclosure is shown.

[0023] Figure 7 is a block diagram of a wireless power transmitter according to another exemplary embodiment of the present disclosure.

[0024] Figure 8 is a block diagram of a wireless power receiver according to another exemplary embodiment of the present invention.

[0025] Fig. 9 An operation state of a wireless power transmitter and a wireless power receiver in a sharing mode according to an exemplary embodiment of the present disclosure is shown.

[0026] Fig.10 is a state diagram illustrating a two-point power calibration method.

[0027] Fig.11 is a graph illustrating a power calibration curve according to a two-point power calibration method.

[0028] Fig.12 is a flow chart illustrating a multi-point power calibration method according to one embodiment.

[0029] Fig.13 The format of a received power packet according to one embodiment is illustrated.

[0030] Fig.14 is a state diagram illustrating a multi-point power calibration method using multiple RP / 2 according to one embodiment.

[0031] Fig.15 is a graph illustrating a power calibration curve according to a multi-point power calibration method using multiple RP / 2 according to one embodiment.

[0032] Fig.16 is a graph illustrating a power calibration curve according to a multi-point power calibration method using a plurality of RP / 2 according to another embodiment.

[0033] Fig.17 is a state diagram illustrating a multi-point power calibration method using RP / 3 according to one embodiment.

[0034] Fig.18 is a graph illustrating a power calibration curve according to a multi-point power calibration method using RP / 3 according to one embodiment.

[0035] Fig.19 is a flow chart illustrating a power recalibration method according to one embodiment.

[0036] Fig. 20 is a state diagram illustrating a power recalibration method according to one embodiment.

[0037] Fig.21 is a graph illustrating a power calibration curve according to a power recalibration method according to one embodiment.

[0038] Fig. 22 is a flow chart illustrating a power calibration method according to one embodiment. DETAILED DESCRIPTION

[0039] In this specification, "A or B" may mean "only A", "only B", or "both A and B". In other words, "A or B" in this specification may be interpreted as "A and / or B". For example, in this specification, "A, B, or C" may mean "only A", "only B", "only C", or any combination of "A, B, and C".

[0040] A slash ( / ) or a comma used in this specification may mean "and / or". For example, "A / B" may mean "A and / or B". Thus, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B, or C".

[0041] In this specification, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, in this specification, the expression "at least one of A or B" or "at least one of A and / or B" may be interpreted as being the same as "at least one of A and B".

[0042] In addition, in this specification, "at least one of A, B, and C" may mean "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B and / or C" may mean "at least one of A, B, and C".

[0043] In addition, the brackets used in this specification may refer to "for example". Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information". In other words, the "control information" in this specification is not limited to "PDCCH", and "PDDCH" may be proposed as an example of "control information". In addition, even when indicated as "control information (ie, PDCCH)", "PDCCH" may be proposed as an example of "control information".

[0044] In this specification, technical features described independently in one figure may be implemented independently or simultaneously. The term "wireless power" used in this specification hereinafter will be used to refer to any form of energy related to electric fields, magnetic fields and electromagnetic fields that is transmitted (or sent) from a wireless power transmitter to a wireless power receiver without using any physical electromagnetic conductors. Wireless power may also be referred to as a wireless power signal, and this may refer to an oscillating magnetic flux surrounded by a primary coil and a secondary coil. For example, power conversion for wireless charging of devices including mobile phones, cordless phones, iPods, MP3 players, headphones, etc. within a system will be described in this specification. Generally, the basic principles of wireless power transmission technology include all of a method of transmitting power by using magnetic coupling, a method of transmitting power by using radio frequency (RF), a method of transmitting power by using microwaves, and a method of transmitting power by using ultrasound (or ultrasonic waves).

[0045] Figure 1 is a block diagram of a wireless power system (10) according to an exemplary embodiment of the present invention.

[0046] refer to Figure 1 , a wireless power system (10) includes a wireless power transmitter (100) and a wireless power receiver (200).

[0047] The wireless power transmitter (100) is supplied with power from an external power source (S) and generates a magnetic field. The wireless power receiver (200) generates a current using the generated magnetic field, thereby being able to wirelessly receive power.

[0048] In addition, in the wireless power system (10), the wireless power transmitter (100) and the wireless power receiver (200) can transceive (send and / or receive) various information required for wireless power transmission. Herein, the communication between the wireless power transmitter (100) and the wireless power receiver (200) can be performed (or established) according to any one of in-band communication using a magnetic field for wireless power transmission (or transmission) and out-of-band communication using a separate communication carrier. Out-of-band communication may also be referred to as out-of-band communication. Hereinafter, out-of-band communication will be mainly described. Examples of out-of-band communication may include NFC, Bluetooth, Bluetooth Low Energy (BLE), etc.

[0049] Here, the wireless power transmitter (100) may be provided as a fixed type or a mobile (or portable) type. Examples of fixed transmitter types may include an embedded type embedded in an indoor ceiling or wall or embedded in furniture such as a table, installed in an outdoor parking lot, bus station, subway station, etc., or installed in a vehicle such as a car or train. The mobile (or portable) type wireless power transmitter (100) may be implemented as a part of another device, for example, a cover of a mobile device or a laptop computer having a portable size or weight, etc.

[0050] In addition, the wireless power receiver (200) should be understood as a comprehensive concept including various household appliances and devices that are operated by being supplied with power wirelessly rather than various electronic devices equipped with batteries and power cables. Typical examples of the wireless power receiver (200) may include portable terminals, cellular phones, smart phones, personal digital assistants (PDAs), portable media players (PDPs), Wibro terminals, tablet PCs, tablet phones, laptop computers, digital cameras, navigation terminals, televisions, electric vehicles (DVs), etc.

[0051] Figure 2 is a block diagram of a wireless power system (10) according to another exemplary embodiment of the present disclosure.

[0052] refer to Figure 2 In the wireless power system (10), there may be one wireless power receiver (200) or a plurality of wireless power receivers. Figure 1 FIG. 4 shows that the wireless power transmitter (100) and the wireless power receiver (200) perform power transmission and reception with each other in a one-to-one correspondence (or relationship), but as shown in FIG. Figure 2 As shown in , one wireless power transmitter (100) is also capable of simultaneously transmitting power to a plurality of wireless power receivers (200-1, 200-2, ..., 200-M). Most specifically, in the case of performing wireless power transmission (or transmission) by using a magnetic resonance method, one wireless power transmitter (100) can transmit power to a plurality of wireless power receivers (200-1, 200-2, ..., 200-M) by using a synchronous transmission (or transmission) method or a time division transmission (or transmission) method.

[0053] In addition, despite Figure 1The wireless power transmitter (100) is shown to transmit (or send) power directly to the wireless power receiver (200), but the wireless power system (10) may also be equipped with a separate wireless power transceiver, such as a relay or repeater, for increasing the wireless power transmission distance between the wireless power transmitter (100) and the wireless power receiver (200). In this case, power is delivered from the wireless power transmitter (100) to the wireless power transceiver, and then the wireless power transceiver can transfer the received power to the wireless power receiver (200).

[0054] Hereinafter, the terms "wireless power receiver", "power receiver" and "receiver" mentioned in this specification will refer to the wireless power receiver (200). In addition, the terms "wireless power transmitter", "power transmitter" and "transmitter" mentioned in the specification will refer to the wireless power transmitter (100).

[0055] Figure 3a Exemplary embodiments of various electronic devices employing wireless power transfer systems are shown.

[0056] like Figure 3a As shown in , electronic devices included in the wireless power transmission system are classified according to the amount of transmission power and the amount of reception power. Figure 3a , wearable devices such as smart watches, smart glasses, head-mounted displays (HMDs), smart rings, etc., and mobile electronic devices (or portable electronic devices) such as headphones, remote controllers, smart phones, PDAs, tablet PCs, etc. can adopt low-power (approximately 5 W or less or approximately 20 W or less) wireless charging methods.

[0057] Small / medium-sized electronic devices such as laptop computers, robot vacuum cleaners, TV receivers, audio devices, vacuum cleaners, monitors, etc. can adopt medium-power (less than about 50W or less than about 200W) wireless charging methods. Kitchen appliances such as blenders, microwave ovens, rice cookers, etc. and personal transportation devices (or other electric devices or vehicles) such as electric wheelchairs, electric bicycles, electric bikes, electric cars, etc. can adopt high-power (less than about 2kW or less than about 22kW) wireless charging methods.

[0058] The above description (or Figure 1 The electric device or vehicle shown in the figure may include a wireless power receiver, which will be described in detail below. Then, the electric device or vehicle may be charged (or recharged) by wirelessly receiving power from the wireless power transmitter.

[0059] Hereinafter, although the present disclosure will be described based on a mobile device adopting a wireless power charging method, this is merely exemplary. And, therefore, it should be understood that the wireless charging method according to the present disclosure can be applied to various electronic devices.

[0060] Standards for wireless power transmission (or delivery) include the Wireless Power Consortium (WPC), the Air Fuel Alliance (AFA), and the Power Management Alliance (PMA).

[0061] The WPC standard defines a baseline power profile (BPP) and an extended power profile (EPP). BPP is related to wireless power transmitters and wireless power receivers that support 5W power transmission, and EPP is related to wireless power transmitters and wireless power receivers that support transmission in a power range greater than 5W and less than 30W.

[0062] Various wireless power transmitters and wireless power receivers respectively using different power levels may be covered by each standard and may be classified by different power classes or categories.

[0063] For example, WPC may classify (or categorize) wireless power transmitters and wireless power receivers into PC-1, PC0, PC1, and PC2, and WPC may provide standard documents (or specifications) for each power class (PC). The PC-1 standard relates to wireless power transmitters and receivers that provide a guaranteed power of less than 5 W. Applications of PC-1 include wearable devices such as smart watches.

[0064] The PC0 standard relates to wireless power transmitters and receivers that provide a guaranteed power of 5W. The PC0 standard includes an EPP with a guaranteed power range extended to 30W. Although in-band (IB) communication corresponds to the mandatory communication protocol of PC0, out-of-band (OB) communication, which is used as an optional backup channel, can also be used for PC0. A wireless power receiver can be identified by setting an OB flag in a configuration packet, and the OB flag indicates whether OB is supported. A wireless power transmitter that supports OB can enter the OB switching phase by sending a bit pattern for OB switching as a response to a configuration packet. The response to the configuration packet can correspond to NAK, ND, or a newly defined 8-bit pattern. Applications of PC0 include smartphones.

[0065] The PC1 standard relates to wireless power transmitters and receivers that provide guaranteed power ranging from 30W to 150W. OB corresponds to a mandatory communication channel for PC1, and IB is used for initialization and link establishment with OB. The wireless power transmitter can enter the OB switching phase by sending a bit pattern for OB switching as a response to a configuration packet. Applications of PC1 include laptop computers or power tools.

[0066] The PC2 standard relates to wireless power transmitters and receivers that provide guaranteed power ranging from 200 W to 2 kW, and its applications include kitchen appliances.

[0067] As described above, PCs can be distinguished according to corresponding power levels. In addition, information about whether compatibility between the same PCs is supported may be optional or mandatory. Here, compatibility between the same PCs indicates that power transmission / reception between the same PCs is possible. For example, in a case where a wireless power transmitter corresponding to PC x is capable of performing charging of a wireless power receiver having the same PC x, it is understood that compatibility between the same PCs is maintained. Similarly, compatibility between different PCs may also be supported. Here, compatibility between different PCs indicates that power transmission / reception between different PCs is also possible. For example, in a case where a wireless power transmitter corresponding to PC x is capable of performing charging of a wireless power receiver having PC y, it is understood that compatibility between different PCs is maintained.

[0068] Support for compatibility between PCs corresponds to an extremely important issue in terms of infrastructure establishment and user experience. However, here, there are various problems to be described below in maintaining compatibility between PCs.

[0069] In the case of compatibility between the same PCs, for example, in the case of a wireless power receiver using a laptop charging method (where stable charging is possible only when power is continuously transmitted), even if its corresponding wireless power transmitter has the same PC, it is difficult for the corresponding wireless power receiver to stably receive power from a wireless power transmitter of a power tool method that transmits power discontinuously. In addition, in the case of compatibility between different PCs, for example, in the case where a wireless power transmitter with a minimum guaranteed power of 200W transmits power to a wireless power receiver with a maximum guaranteed power of 5W, the corresponding wireless power receiver may be damaged due to overvoltage. Therefore, it may be inappropriate (or difficult) to use PS as an index / reference standard to represent / indicate compatibility.

[0070] The wireless power transmitter and receiver can provide a very convenient user experience and interface (UX / UI). That is, a smart wireless charging service can be provided, and the smart wireless charging service can be implemented based on the UX / UI of a smartphone including a wireless power transmitter. For these applications, the interface between the processor of the smartphone and the wireless charging receiver allows "put and use" two-way communication between the wireless power transmitter and the wireless power receiver.

[0071] As an example, a user can experience the smart wireless charging service in a hotel. When the user enters the hotel room and places the smartphone on the wireless charger in the room, the wireless charger sends wireless power to the smartphone, and the smartphone receives wireless power. In this process, the wireless charger sends information about the smart wireless charging service to the smartphone. When it is detected that the smartphone is on the wireless charger, when it is detected that wireless power is received, or when the smartphone receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state of asking the user for consent (opt-in) for supplementary features. For this purpose, the smartphone can display a message on the screen with or without an alarm sound. An example of a message may include a phrase "Welcome to ### Hotel. Select "Yes" to enable the smart charging function: Yes | No, thank you". The smartphone receives input from the user who selects "Yes" or "No, thank you" and executes the next process selected by the user. If "Yes" is selected, the smartphone will send the corresponding information to the wireless charger. The smartphone and the wireless charger perform the smart charging function together.

[0072] Smart wireless charging services can also include receiving automatically populated Wi-Fi credentials. For example, the wireless charger sends the WiFi credentials to the smartphone, and the smartphone automatically enters the WiFi credentials received from the wireless charger by running an appropriate application.

[0073] Smart wireless charging services may also include running hotel apps that offer hotel promotions or obtain remote check-in / check-out and contact information.

[0074] As another example, the user can experience the smart wireless charging service in the vehicle. When the user enters the vehicle and places the smartphone on the wireless charger, the wireless charger sends wireless power to the smartphone, and the smartphone receives the wireless power. In this process, the wireless charger sends information about the smart wireless charging service to the smartphone. When it is detected that the smartphone is on the wireless charger, when it is detected that wireless power is to be received, or when the smartphone receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state of asking the user to check the identity.

[0075] In this state, the smartphone automatically connects to the vehicle via WiFi or Bluetooth. The smartphone can display a message on the screen with or without an alarm sound. An example of a message may include the phrase "Welcome to your car. Select "Yes" to synchronize the device with the in-vehicle controls: Yes | No, thanks". After receiving the user's input selecting "Yes" or "No, thanks", the smartphone executes the next process selected by the user. If "Yes" is selected, the smartphone will send the corresponding information to the wireless charger. In addition, the smartphone and the wireless charger can run the in-vehicle intelligent control function together by driving the in-vehicle application / display software. The user can enjoy the desired music and check regular map locations. The in-vehicle application / display software may include the ability to provide synchronized access to passers-by.

[0076] As another example, the user can experience smart wireless charging at home. When the user enters the room and places the smartphone on the wireless charger in the room, the wireless charger sends wireless power to the smartphone, and the smartphone receives wireless power. In this process, the wireless charger sends information about the smart wireless charging service to the smartphone. When it is detected that the smartphone is on the wireless charger, when it is detected that wireless power is to be received, or when the smartphone receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state of asking the user for consent (opt-in) of the supplementary features. For this purpose, the smartphone can display a message on the screen with or without an alarm sound. Examples of the message may include phrases such as "Hi, xxx, do you want to enable night mode and protect the building? : Yes | No, thank you." The smartphone receives user input selecting "Yes" or "No, thank you" and executes the next process selected by the user. If "Yes" is selected, the smartphone sends the corresponding information to the wireless charger. The smartphone and the wireless charger can at least recognize the user's mode and suggest that the user lock the doors and windows, turn off the lights, or set an alarm.

[0077] Hereinafter, a "profile" will be newly defined based on an index / reference standard representing / indicating compatibility. More specifically, it can be understood that by maintaining compatibility between a wireless power transmitter and a receiver having the same "profile", stable power transmission / reception can be performed, and power transmission / reception between a wireless power transmitter and a receiver having different "profiles" cannot be performed. A "profile" may be defined based on compatibility and / or application without considering (or independently of) power level.

[0078] For example, profiles may be divided into 3 different categories such as i) Mobile, ii) Power Tools, and iii) Kitchen.

[0079] As another example, profiles may be divided into 4 different categories such as i) mobile, ii) power tools, iii) kitchen, and iv) wearable.

[0080] In the case of a “mobile” profile, the PC may be defined as PC0 and / or PC1, the communication protocol / method may be defined as IB and OB communications, and the operating frequency may be defined as 87 to 205 kHz, while smartphones, laptops, etc. may exist as exemplary applications.

[0081] In the case of the “power tool” profile, the PC may be defined as PC1, the communication protocol / method may be defined as IB communication, the operating frequency may be defined as 87 to 145 kHz, and power tools and the like may exist as exemplary applications.

[0082] In the case of the “kitchen” profile, the PC may be defined as PC2, the communication protocol / method may be defined as NFC-based communication, the operating frequency may be defined as less than 100 kHz, and kitchen / home appliances, etc. may exist as exemplary applications.

[0083] In the case of the power tool and kitchen profile, NFC communication may be used between the wireless power transmitter and the wireless power receiver. The wireless power transmitter and the wireless power receiver may confirm that they are mutually NFC devices by exchanging WPC NFC Data Exchange Profile Format (NDEF).

[0084] Figure 3b An example of WPC NDEF in a wireless power transfer system is shown.

[0085] refer to Figure 3b , WPC NDEF may include, for example, an application profile field (e.g., 1B), a version field (e.g., 1B), and profile-specific data (e.g., 1B). The application profile field indicates whether the corresponding device is i) mobile and computing, ii) power tool, and iii) kitchen, and the upper nibble in the version field indicates the major version and the lower nibble indicates the minor version. In addition, the profile-specific data defines the content for the kitchen.

[0086] In the case of a “wearable” profile, a PC may be defined as PC-1, a communication protocol / method may be defined as IB communication, an operating frequency may be defined as 87 to 205 kHz, and a wearable device worn by a user, etc. may exist as an exemplary application.

[0087] Maintaining compatibility between the same profiles may be mandatory, and maintaining compatibility between different profiles may be optional.

[0088] The above-mentioned profiles (mobile profile, power tool profile, kitchen profile, and wearable profile) may be summarized and represented as first to nth profiles, and new profiles may be added / replaced according to the WPC standard and exemplary embodiments.

[0089] When the profile is defined as described above, the wireless power transmitter can optionally perform power transmission only to the wireless power receiver corresponding to the same profile as the wireless power transmitter, thereby being able to perform more stable power transmission. In addition, since the load (or burden) of the wireless power transmitter can be reduced and power transmission to a wireless power receiver that is not likely to be compatible is not attempted, the risk of damage to the wireless power receiver can be reduced.

[0090] PC1 of the "mobile" profile may be defined by deriving from optional extensions such as OOB based on PC0. Also, the "power tool" profile may be defined as a simply modified version of the PC1 "mobile" profile. In addition, although profiles have been defined so far for the purpose of maintaining compatibility between the same profiles, in the future, technology may evolve to a level that maintains compatibility between different profiles. A wireless power transmitter or wireless power receiver may use various methods to notify (or announce) its profile to its peer.

[0091] In the AFA standard, a wireless power transmitter is called a power transmission unit (PTU), and a wireless power receiver is called a power reception unit (PRU). Also, PTUs are classified into multiple levels as shown in Table 1, and PRUs are classified into multiple levels as shown in Table 2.

[0092] [Table 1]

[0093] <![CDATA[P TX_IN_MAX ]]> Minimum Class Support Requirements Minimum value of the maximum number of supported devices Level 1 2W 1x Category 1 1x Category 1 Level 2 10W 1x Category 3 2x Category 2 Level 3 16W 1x Category 4 2x Category 3 Level 4 33W 1x Category 5 3x Category 3 Level 5 50W 1x Category 6 4x Category 3 Level 6 70W 1x Category 7 5x Category 3

[0094] [Table 2]

[0095] PRU <![CDATA[P RX_OUT_MAX' ]]> Example Applications Category 1 TBD Bluetooth Headset Category 2 3.5W Feature Phone Category 3 6.5W Smartphone Category 4 13W Tablet PC, Tablet Phone Category 5 25W Small laptop computer Category 6 37.5W Ordinary laptop Category 7 50W Home appliances

[0096] As shown in Table 1, the maximum output power capability of a Class n PTU can be equal to or greater than the corresponding Class PTU. TX_IN_MAX A PRU cannot draw power higher than the power level specified in the corresponding class.

[0097] Figure 4 is a block diagram of a wireless power transmission system according to another exemplary embodiment of the present disclosure.

[0098] refer to Figure 4 , a wireless power transmission system (10) includes a mobile device (450) that wirelessly receives power and a base station (400) that wirelessly transmits power.

[0099] As a device for providing inductive power or resonance power, the base station (400) may include at least one of a wireless power transmitter (100) and a system unit (405). The wireless power transmitter (100) may transmit inductive power or resonance power, and may control the transmission. The wireless power transmitter (100) may include a power conversion circuit (110) that converts electrical energy into a power signal by generating a magnetic field via one or more primary coils, and a communication and control unit (120) that controls communication and power transmission between wireless power receivers (200) so as to transmit an appropriate (or suitable) level of power. The system unit (405) may perform input power supply, control of multiple wireless power transmitters, and other operation controls (e.g., user interface control) of the base station (400).

[0100] The primary coil can generate an electromagnetic field by using alternating current power (or voltage or current). The primary coil is supplied with alternating current power (or voltage or current) of a specific frequency, which is output from the power conversion circuit (110). Therefore, the primary coil can generate a magnetic field of a specific frequency. A magnetic field of a non-radial shape or a radial shape can be generated. In addition, the wireless power receiver (200) receives the generated magnetic field and then generates a current. In other words, the primary coil transmits power wirelessly.

[0101] In the magnetic induction method, the primary coil and the secondary coil may have random appropriate shapes. For example, the primary coil and the secondary coil may correspond to a copper wire wound around a highly permeable magnetic formation (e.g., ferrite or amorphous metal). The primary coil may also be referred to as a primary magnetic core, a primary winding, a primary loop antenna, etc. In addition, the secondary coil may also be referred to as a secondary magnetic core, a secondary winding, a secondary loop antenna, a pickup antenna, etc.

[0102] In the case of using a magnetic resonance method, a primary coil and a secondary coil may be provided in the form of a primary resonance antenna and a secondary resonance antenna, respectively. The resonance antenna may have a resonance structure including a coil and a capacitor. At this time, the resonance frequency of the resonance antenna may be determined by the inductance of the coil and the capacitance of the capacitor. Here, the coil may be formed to have a loop shape. In addition, a magnetic core may be placed in the loop. The magnetic core may include a physical magnetic core such as a ferrite core or an air magnetic core.

[0103] The energy transmission (or transmission) between the primary resonant antenna and the secondary resonant antenna can be performed by a resonance phenomenon occurring in a magnetic field. When a near field corresponding to the resonant frequency appears in the resonant antenna, and when another resonant antenna exists near the corresponding resonant antenna, the resonance phenomenon refers to the efficient energy transmission occurring between two mutually coupled resonant antennas. When a magnetic field corresponding to the resonant frequency is generated between the primary resonant antenna and the secondary resonant antenna, the primary resonant antenna and the secondary resonant antenna resonate with each other. Therefore, in general, the magnetic field is more efficiently gathered toward the second resonant antenna than when the magnetic field generated from the primary antenna is radiated into free space. Therefore, energy can be efficiently transmitted from the first resonant antenna to the second resonant antenna. The magnetic induction method can be implemented similarly to the magnetic resonance method. However, in this case, the frequency of the magnetic field is not required to be the resonant frequency. However, in the magnetic induction method, the loops configuring the primary coil and the secondary coil are required to match each other, and the distance between the loops should be very close.

[0104] Although not shown in the drawings, the wireless power transmitter (100) may further include a communication antenna. In addition to magnetic field communication, the communication antenna may send and / or receive communication signals by using a communication carrier. For example, the communication antenna may send and / or receive communication signals corresponding to WiFi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0105] The communication and control unit (120) may transmit information to the wireless power receiver (200) and / or receive information from the wireless power receiver (200). The communication and control unit (120) may include at least one of an IB communication module and an OB communication module.

[0106] The IB communication module can send and / or receive information by using electromagnetic waves, which use a specific frequency as its center frequency. For example, the communication and control unit (120) can perform in-band (IB) communication by using a primary coil to send communication information about the operating frequency of wireless power transmission or by using a primary coil to receive communication information about the operating frequency. At this time, the communication and control unit (120) can load information into the electromagnetic wave or interpret the information carried by the electromagnetic wave by using a modulation scheme such as binary phase shift keying (BPSK), frequency shift keying (FSK) or amplitude shift keying (ASK) or a coding scheme such as Manchester coding or non-return to zero level (NZR-L) coding. By using the above-mentioned IB communication, the communication and control unit (120) can send and / or receive information at a data transmission rate of several kbps at a distance of up to several meters.

[0107] The OB communication module may also perform out-of-band communication via a communication antenna. For example, the communication and control unit (120) may be configured for a near field communication module. Examples of near field communication modules may include communication modules such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0108] The communication and control unit (120) can control the overall operation of the wireless power transmitter (100). The communication and control unit (120) can perform calculation and processing of various information, and can also control each configuration element of the wireless power transmitter (100).

[0109] The communication and control unit (120) may be implemented in a computer or similar device such as hardware, software, or a combination thereof. When implemented in a hardware form, the communication and control unit (120) may be provided as an electronic circuit that performs a control function by processing an electrical signal. And, when implemented in a software form, the communication and control unit (120) may be provided as a program that operates the communication and control unit (120).

[0110] By controlling the operating point, the communication and control unit (120) can control the transmission power. The controlled operating point can correspond to a combination of frequency (or phase), duty cycle, duty ratio and voltage amplitude. The communication and control unit (120) can control the transmission power by adjusting any one of the frequency (or phase), duty cycle, duty ratio and voltage amplitude. In addition, the wireless power transmitter (100) can provide a constant level of power, and the wireless power receiver (200) can control the level of received power by controlling the resonant frequency.

[0111] The mobile device (450) includes a wireless power receiver (200) that receives wireless power through a secondary coil and a load (455) that receives and stores the power received by the wireless power receiver (200) and supplies the received power to the device.

[0112] The wireless power receiver (200) may include a power pickup circuit (210) and a communication and control unit (220). The power pickup circuit (210) may receive wireless power through a secondary coil and may convert the received wireless power into electrical energy. The power pickup circuit (210) may rectify an alternating current (AC) signal received through the secondary coil and convert the rectified signal into a direct current (DC) signal. The communication and control unit (220) may control the transmission and reception of wireless power (transmission and reception of power).

[0113] The secondary coil can receive wireless power transmitted from the wireless power transmitter (100). The secondary coil can receive power by using the magnetic field generated in the primary coil. Here, in the case where the specific frequency corresponds to the resonance frequency, magnetic resonance can occur between the primary coil and the secondary coil, thereby allowing power to be transmitted more efficiently.

[0114] Despite Figure 4 Although not shown, the communication and control unit (220) may also include a communication antenna. The communication antenna may send and / or receive communication signals by using a communication carrier other than magnetic field communication. For example, the communication antenna may send and / or receive communication signals corresponding to Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0115] The communication and control unit (220) may transmit information to the wireless power transmitter (100) and / or receive information from the wireless power transmitter (100). The communication and control unit (220) may include at least one of an IB communication module and an OB communication module.

[0116] The IB communication module can send and / or receive information by using electromagnetic waves, which use a specific frequency as its center frequency. For example, the communication and control unit (220) can perform IB communication by loading information into electromagnetic waves and sending information by using a secondary coil or receiving electromagnetic waves carrying information by using a secondary coil. At this time, the communication and control unit (120) can load information into electromagnetic waves or interpret the information carried by electromagnetic waves by using modulation schemes such as binary phase shift keying (BPSK), frequency shift keying (FSK) or amplitude shift keying (ASK) or encoding schemes such as Manchester encoding or non-return-to-zero level (NZR-L) encoding. By using the above-mentioned IB communication, the communication and control unit (220) can send and / or receive information at a data transmission rate of several kbps at a distance of up to several meters.

[0117] The OB communication module may also perform out-of-band communication via a communication antenna. For example, the communication and control unit (220) may be configured for a near field communication module.

[0118] Examples of the near field communication module may include communication modules such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, and the like.

[0119] The communication and control unit (220) can control the overall operation of the wireless power receiver (200). The communication and control unit (220) can perform calculation and processing of various information, and can also control each configuration element of the wireless power receiver (200).

[0120] The communication and control unit (220) may be implemented in a computer or similar device such as hardware, software, or a combination thereof. When implemented in a hardware form, the communication and control unit (220) may be provided as an electronic circuit that performs a control function by processing an electrical signal. And, when implemented in a software form, the communication and control unit (220) may be provided as a program that operates the communication and control unit (220).

[0121] Hereinafter, the coil or the coil unit includes a coil and at least one device close to the coil, and the coil or the coil unit may also be referred to as a coil assembly, a coil unit, or a unit.

[0122] Figure 5 It is a state transition diagram used to describe the wireless power transfer process.

[0123] refer to Figure 5 , power transmission (or transmission) from a wireless power transmitter to a wireless power receiver according to an exemplary embodiment of the present disclosure can be roughly divided into a selection phase (510), a ping phase (520), an identification and configuration phase (530), a negotiation phase (540), a calibration phase (550), a power transmission phase (560) and a renegotiation phase (570).

[0124] If a specific error or a specific event is detected when initiating power transfer or while maintaining power transfer, the selection phase (510) may include shift phases (or steps) - reference numerals S502, S504, S508, S510 and S512. Here, the specific error or specific event will be specified in the following description. In addition, during the selection phase (510), the wireless power transmitter may monitor whether there is an object on the interface surface. If the wireless power transmitter detects that an object is placed on the interface surface, the processing step may be transferred to the ping phase (520). During the selection phase (510), the wireless power transmitter may send an analog ping with a power signal (or pulse) corresponding to a very short duration, and may detect whether there is an object in the effective area of ​​the interface surface based on the current change in the transmitting coil or the primary coil.

[0125] In the case where an object is sensed (or detected) in the selection phase (510), the wireless power transmitter may measure the quality factor of the wireless power resonant circuit (e.g., a power transmission coil and / or a resonant capacitor). According to an exemplary embodiment of the present disclosure, during the selection phase (510), the wireless power transmitter may measure the quality factor in order to determine whether a foreign object is present in the charging area together with the wireless power receiver. In the coil provided in the wireless power transmitter, the components of the inductance and / or the series resistance may decrease due to changes in the environment, and due to such a decrease, the value of the quality factor may also decrease. In order to determine whether a foreign object exists by using the measured quality factor value, the wireless power transmitter may receive a reference quality factor value from the wireless power receiver, which is pre-measured in a state where no foreign object is placed in the charging area. The wireless power transmitter may determine whether a foreign object exists by comparing the measured quality factor value with the reference quality factor value received during the negotiation phase (540). However, in the case of a wireless power receiver having a low reference quality factor value, for example, the wireless power receiver may have a low reference quality factor value according to its type, purpose, characteristics, etc., in the presence of foreign matter, since the difference between the reference quality factor value and the measured quality factor value is small (or not large), there may be a problem that the presence of foreign matter cannot be easily determined. Therefore, in this case, other determination factors should be further considered, or the presence or absence of foreign matter should be determined by using another method.

[0126] According to another exemplary embodiment of the present disclosure, in the case where an object is sensed (or detected) in the selection phase (510), in order to determine whether there is a foreign object in the charging area together with the wireless power receiver, the wireless power transmitter may measure a quality factor value within a specific frequency region (e.g., an operating frequency region). In a coil provided in the wireless power transmitter, due to changes in the environment, the components of the inductance and / or series resistance may decrease, and due to such a decrease, the resonant frequency of the coil of the wireless power transmitter may change (or shift). More specifically, the quality factor peak frequency corresponding to the frequency at which the maximum quality factor value is measured within the operating frequency band may move (or shift).

[0127] In the ping phase (520), if the wireless power transmitter detects the presence of an object, the transmitter activates (or wakes up) the receiver and sends a digital ping for identifying whether the detected object corresponds to the wireless power receiver. During the ping phase (520), if the wireless power transmitter fails to receive a response signal (e.g., a signal strength packet) to the digital ping from the receiver, the process may return to the selection phase (510). In addition, in the ping phase (520), if the wireless power transmitter receives a signal indicating that the power transfer is complete (e.g., a charging completion packet) from the receiver, the process may return to the selection phase (510).

[0128] If the ping phase (520) is complete, the wireless power transmitter may transition to an identification and configuration phase (530) for identifying the receiver and for collecting configuration and status information.

[0129] In the identification and configuration stage (530), if the wireless power transmitter receives an unwanted packet (i.e., an unexpected packet), or if the wireless power transmitter fails to receive a packet during a predetermined time period (i.e., a timeout), or if a packet transmission error occurs (i.e., a transmission error), or if no power contract is configured for transmission (i.e., no power transmission contract), the wireless power transmitter can transfer to the selection stage (510).

[0130] The wireless power transmitter may confirm (or verify) whether it is necessary to enter the negotiation phase (540) based on the negotiation field value of the configuration packet received during the identification and configuration phase (530). Based on the verification result, if negotiation is required, the wireless power transmitter enters the negotiation phase (540) and may then perform a predetermined FOD detection process. On the contrary, if negotiation is not required, the wireless power transmitter may immediately enter the power transmission phase (560).

[0131] In the negotiation phase (540), the wireless power transmitter may receive a foreign object detection (FOD) status packet including a reference quality factor value. Alternatively, the wireless power transmitter may receive a FOD status packet including a reference peak frequency value. Alternatively, the wireless power transmitter may receive a status packet including a reference quality factor value and a reference peak frequency value. At this time, the wireless power transmitter may determine a quality factor threshold for FO detection based on the reference quality factor value. The wireless power transmitter may determine a peak frequency threshold for FO detection based on the reference peak frequency value.

[0132] The wireless power transmitter can detect the presence or absence of FO in the charging area by using the determined quality factor threshold for FO detection and the currently measured quality factor value (i.e., the quality factor value measured before the ping stage), and then the wireless power transmitter can control the transmission power according to the FO detection result. For example, in the case of detecting FO, power transmission can be stopped. However, the present invention is not limited to this.

[0133] The wireless power transmitter can detect the presence or absence of FO in the charging area by using the determined peak frequency threshold for FO detection and the currently measured peak frequency value (i.e., the peak frequency value measured before the ping stage), and then the wireless power transmitter can control the transmission power according to the FO detection result. For example, in the case of detecting FO, power transmission can be stopped. However, the present invention is not limited to this.

[0134] In the event that FO is detected, the wireless power transmitter may return to the selection phase (510). Conversely, in the event that FO is not detected, the wireless power transmitter may proceed to the calibration phase (550) and may then enter the power transmission phase (560). More specifically, in the event that FO is not detected, the wireless power transmitter may determine the strength of the received power received by the receiving end during the calibration phase (550), and may measure the power loss in the receiving end and the transmitting end in order to determine the strength of the power sent from the transmitting end. In other words, during the calibration phase (550), the wireless power transmitter may estimate the power loss based on the difference between the transmitting power of the transmitting end and the receiving power of the receiving end. A wireless power transmitter according to an exemplary embodiment of the present invention may calibrate a threshold for FOD detection by applying the estimated power loss.

[0135] In the power transfer stage (560), if the wireless power transmitter receives an unwanted packet (i.e., an unexpected packet), or if the wireless power transmitter fails to receive a packet during a predetermined time period (i.e., a timeout), or if a predetermined power transfer contract is violated (i.e., a power transfer contract violation), or if charging is completed, the wireless power transmitter may transfer to the selection stage (510).

[0136] In addition, in the power transmission phase (560), if the wireless power transmitter needs to reconfigure the power transmission contract according to the state change in the wireless power transmitter, the wireless power transmitter can transfer to the re-negotiation phase (570). At this time, if the re-negotiation is successfully completed, the wireless power transmitter can return to the power transmission phase (560).

[0137] In this embodiment, the calibration step 550 and the power transmission stage 560 are divided into separate steps, but the calibration step 550 may be integrated into the power transmission stage 560. In this case, the operation in the calibration step 550 may be performed in the power transmission stage 560.

[0138] The power transmission contract described above may be configured based on the status and characteristic information of the wireless power transmitter and the receiver. For example, the wireless power transmitter status information may include information about the maximum amount of transmittable power, information about the maximum number of receivers that can be accommodated, etc. In addition, the receiver status information may include information about the required power, etc.

[0139] Figure 6 A power control method according to an exemplary embodiment of the present disclosure is shown.

[0140] like Figure 6 As shown, in the power transmission stage (560), by alternating power transmission and / or reception with communication, the wireless power transmitter (100) and the wireless power receiver (200) can control the amount (or size) of the power transmitted. The wireless power transmitter and the wireless power receiver operate at a specific control point. The control point indicates a combination of voltage and current provided from the output terminal of the wireless power receiver when performing power transmission.

[0141] More specifically, the wireless power receiver selects a desired control point, a desired output current / voltage, a temperature at a specific location of the mobile device, etc., and additionally determines an actual control point at which the receiver is currently operating. The wireless power receiver calculates a control error value by using the desired control point and the actual control point, and then the wireless power receiver can send the calculated control error value as a control error packet to the wireless power transmitter.

[0142] In addition, the wireless power transmitter can use the received control error packet to configure / control a new operating point - amplitude, frequency, and duty cycle to control power transmission. The control error packet can then be sent / received at constant time intervals during the power transmission phase, and according to an exemplary embodiment, when the wireless power receiver attempts to reduce the current of the wireless power transmitter, the wireless power receiver can send the control error packet by setting the control error value to a negative number. And, in the case where the wireless power receiver wants to increase the current of the wireless power transmitter, the wireless power receiver sends the control error packet by setting the control error value to a positive number. During the induction mode, the wireless power receiver can control power transmission by sending the control error packet to the wireless power transmitter as described above.

[0143] In the resonance mode, which will be described in detail below, the device can be operated by using a method different from that in the induction mode. In the resonance mode, one wireless power transmitter should be able to serve multiple wireless power receivers at the same time. However, in the case where power transmission is controlled only as in the induction mode, since the transmitted power is controlled by communication established with one wireless power receiver, it may be difficult to control the power transmission of another wireless power receiver. Therefore, in the resonance mode according to the present invention, the following method is used: the amount of received power is controlled by causing the wireless power transmitter to normally transmit (or send) basic power and causing the wireless power receiver to control its own resonant frequency. However, even during operation in the resonance mode, the above is not completely excluded. Figure 6 Furthermore, additional control of the transmit power can be achieved by using Figure 6 method to execute.

[0144] Figure 7 1 is a block diagram of a wireless power transmitter according to another exemplary embodiment of the present disclosure. This may belong to a wireless power transmission system operating in a magnetic resonance mode or a sharing mode. The sharing mode may refer to a mode in which many-to-one (or one-to-many) communication and charging are performed between a wireless power transmitter and a wireless power receiver. The sharing mode may be implemented as a magnetic induction method or a resonance method.

[0145] refer to Figure 7 The wireless power transmitter (700) may include at least one of a cover (720) covering the coil assembly, a power adapter (730) supplying power to the power transmitter (740), the power transmitter (740) transmitting wireless power, and a user interface (750) providing information related to the power transmission process and other related information. More specifically, the user interface (750) may be optionally included or may be included as another user interface (750) of the wireless power transmitter (700).

[0146] The power transmitter (740) may include at least one of a coil assembly (760), an impedance matching circuit (770), an inverter (780), a communication circuit (790), and a control circuit (710).

[0147] The coil assembly (760) includes at least one primary coil for generating a magnetic field. Also, the coil assembly (760) may also be referred to as a coil unit.

[0148] The impedance matching circuit (770) can provide impedance matching between the inverter and the primary coil (s). The impedance matching circuit (770) can generate resonance from an appropriate frequency that increases the current of the primary coil (s). In a multi-coil power transmitter (740), the impedance matching circuit can additionally include a multiplexer that routes signals from the inverter to a subset of the primary coils. The impedance matching circuit can also be referred to as an oscillating circuit.

[0149] The impedance matching circuit (770) may include a capacitor, an inductor, and a switching device for switching the connection between the capacitor and the inductor. Impedance matching may be performed by detecting a reflected wave of wireless power transmitted (or sent) through the coil assembly (760) and switching the switching device based on the detected reflected wave, thereby adjusting the connection state of the capacitor or the inductor or adjusting the capacitance of the capacitor or adjusting the inductance of the inductor. In some cases, impedance matching may be achieved even if the impedance matching circuit (770) is omitted. The present specification also includes an exemplary embodiment of a wireless power transmitter (700) in which the impedance matching circuit (770) is omitted.

[0150] The inverter (780) can convert the DC input into an AC signal. The inverter (780) can operate as a half-bridge inverter or a full-bridge inverter to generate duty cycle and pulse waves with adjustable frequency. In addition, the inverter can include multiple stages to adjust the input voltage level.

[0151] The communication circuit (790) can perform communication with the power receiver. The power receiver performs load modulation to transmit information and requests corresponding to the power transmitter. Therefore, the power transmitter (740) can use the communication circuit (790) to monitor the amplitude and / or phase of the current and / or voltage of the primary coil to demodulate the data sent from the power receiver.

[0152] In addition, the power transmitter (740) may control output power by using a frequency shift keying (FSK) method or the like so that data can be transmitted through the communication circuit (790).

[0153] The control circuit (710) can control the communication and power transmission (or delivery) of the power transmitter (740). The control circuit (710) can control the power transmission by adjusting the above-mentioned operating point. The operating point can be determined by at least any one of the operating frequency, duty cycle and input voltage, for example.

[0154] The communication circuit (790) and the control circuit (710) may be provided as separate units / devices / chip sets, respectively, or may be provided as one unit / device / chip set.

[0155] Figure 8A wireless power receiver according to another exemplary embodiment of the present disclosure is shown. This may belong to a wireless power transmission system operating in a magnetic resonance mode or a sharing mode.

[0156] refer to Figure 8 The wireless power receiver (800) may include at least one of a user interface (820) providing information related to the power transmission process and other related information, a power receiver (830) receiving wireless power, a load circuit (840), and a base (850) supporting and covering the coil assembly. More specifically, the user interface (820) may be optionally included, or may be included as another user interface (820) of the wireless power receiver (800).

[0157] The power receiver (830) may include at least one of a power converter (860), an impedance matching circuit (870), a coil assembly (880), a communication circuit (890), and a control circuit (810).

[0158] The power converter (860) can convert the AC power received from the secondary coil into a voltage and current suitable for a load circuit. According to an exemplary embodiment, the power converter (860) may include a rectifier. The rectifier can rectify the received wireless power and can convert power from alternating current (AC) to direct current (DC). The rectifier can convert alternating current to direct current using a diode or a transistor, and then the rectifier can use a capacitor and a resistor to smooth the converted current. Here, a full-wave rectifier, a half-wave rectifier, a voltage doubler, etc. implemented as a bridge circuit can be used as a rectifier. In addition, the power converter can adapt the reflected impedance of the power receiver.

[0159] The impedance matching circuit (870) can provide impedance matching between the secondary coil and the combination of the power converter (860) and the load circuit (840). According to an exemplary embodiment, the impedance matching circuit can generate a resonance of about 100kHz, which can enhance power transmission. The impedance matching circuit (870) can include a capacitor, an inductor, and a switching device that switches the combination of the capacitor and the inductor. Impedance matching can be performed by controlling the switching devices of the circuit constituting the impedance matching circuit (870) based on the voltage value, current value, power value, frequency value, etc. of the received wireless power. In some cases, impedance matching can be achieved even if the impedance matching circuit (870) is omitted. The present specification also includes an exemplary embodiment of a wireless power receiver (200) in which the impedance matching circuit (870) is omitted.

[0160] The coil assembly (880) includes at least one secondary coil, and optionally, the coil assembly (880) may also include an element for shielding metal parts of the receiver from magnetic fields.

[0161] The communication circuit (890) may perform load modulation to communicate requests and other information to the power transmitter.

[0162] To this end, the power receiver (830) may perform switching of resistors or capacitors to change the reflected impedance.

[0163] The control circuit (810) can control the received power. To this end, the control circuit (810) can determine / calculate the difference between the actual operating point and the desired operating point of the power receiver (830). Then, by executing a request to adjust the reflected impedance of the power transmitter and / or adjust the operating point of the power transmitter, the difference between the actual operating point and the desired operating point can be adjusted / reduced. In the case of minimizing the difference, optimal power reception can be performed.

[0164] The communication circuit (890) and the control circuit (810) may be provided as different devices / chip sets, or may be provided as one device / chip set.

[0165] Fig. 9 Operation states of a wireless power transmitter and a wireless power receiver in a sharing mode according to an exemplary embodiment of the present disclosure are shown.

[0166] refer to Fig. 9 , a wireless power receiver operating in a sharing mode may operate in any one of a selection phase (1100), an introduction phase (1110), a configuration phase (1120), a negotiation phase (1130), and a power transmission phase (1140).

[0167] First, the wireless power transmitter according to an exemplary embodiment of the present disclosure may transmit a wireless power signal to detect a wireless power receiver. More specifically, the process of detecting a wireless power receiver using a wireless power signal may be referred to as a simulated ping.

[0168] In addition, the wireless power receiver that receives the wireless power signal may enter the selection phase ( 1100 ). As described above, the wireless power receiver that enters the selection phase ( 1100 ) may detect the presence or absence of the FSK signal in the wireless power signal.

[0169] In other words, the wireless power receiver may perform communication by using any one of the exclusive mode and the sharing mode according to the presence or absence of the FSK signal.

[0170] More specifically, in case that the FSK signal is included in the wireless power signal, the wireless power receiver may operate in the sharing mode, otherwise the wireless power receiver may operate in the exclusive mode.

[0171] In the case where the wireless power receiver operates in the sharing mode, the wireless power receiver may enter the introduction phase (1110). In the introduction phase (1110), the wireless power receiver may send a control information (CI) packet to the wireless power transmitter to send the control information packet during the configuration phase, the negotiation phase, and the power transmission phase. The control information packet may have a header and information about control. For example, in the control information packet, the header may correspond to 0X53.

[0172] In the introduction phase (1110), the wireless power receiver performs an attempt to request a free time slot for sending a control information (CI) packet during the subsequent configuration phase, negotiation phase, and power transmission phase. At this time, the wireless power receiver selects a free time slot and sends an initial CI packet. If the wireless power transmitter sends ACK as a response to the corresponding CI packet, the wireless power transmitter enters the configuration phase. If the wireless power transmitter sends NACK as a response to the corresponding CI packet, this indicates that another wireless power receiver is performing communication through the configuration and negotiation phases. In this case, the wireless power receiver retries to perform a request for a free time slot.

[0173] If the wireless power receiver receives ACK as a response to the CI packet, the wireless power receiver can determine the position of the dedicated slot in the frame by counting the remaining synchronization slots until the initial frame synchronization. In all subsequent slot-based frames, the wireless power receiver transmits the CI packet through the corresponding slot.

[0174] If the wireless power transmitter authorizes the wireless power receiver to enter the configuration phase, the wireless power transmitter provides a series of lock time slots dedicated to the wireless power receiver. This ensures that the wireless power receiver proceeds to the configuration phase without any conflicts.

[0175] The wireless power receiver transmits a sequence of data packets, for example, two identification data packets (IDHI and IDLO), by using the locked time slots. When this phase is completed, the wireless power receiver enters the negotiation phase. During the negotiation state, the wireless power transmitter continues to provide the locked time slots dedicated to the wireless power receiver. This ensures that the wireless power receiver proceeds to the negotiation phase without any conflicts.

[0176] The wireless power receiver sends one or more negotiation data packets by using the corresponding locked time slot, and the sent (one or more) negotiation data packets can be mixed with the dedicated data packets. Finally, the corresponding sequence ends (or completes) with a specific request (SRQ) packet. When the corresponding sequence is completed, the wireless power receiver enters the power transmission phase, and the wireless power transmitter stops providing the locked time slot.

[0177] In the power transmission phase, the wireless power receiver performs transmission of the CI packet by using the allocated time slot and then receives power. The wireless power receiver may include a regulator circuit. The regulator circuit may be included in the communication / control unit. The wireless power receiver can adjust the reflected impedance of the wireless power receiver by the regulator circuit. In other words, the wireless power receiver can adjust the reflected impedance for the amount of power requested by the external load. This can prevent excessive reception of power and overheating.

[0178] In the sharing mode, since the wireless power transmitter may not perform regulation of power in response to a received CI packet (depending on the operation mode), control may be required in this case to prevent an overvoltage condition.

[0179] Hereinafter, authentication between a wireless power transmission device and a wireless power reception device will be disclosed.

[0180] Assume that when the wireless power transmission device transmits wireless power to the wireless power receiving device, a foreign object is located between the wireless power receiving device and the wireless power transmission device. In this case, the foreign object absorbs part of the magnetic field. In other words, the foreign object receives part of the wireless power transmitted by the wireless power transmission device, and the wireless power receiving device receives the remaining wireless power. In terms of power transmission efficiency, the loss of transmission power is as much as the power or energy absorbed by the foreign object. As mentioned above, because the presence of foreign matter and power loss (P loss ), so the wireless power transmission device can detect foreign matter based on how much power loss has occurred. The above foreign matter detection method can be called a foreign matter detection method based on power loss.

[0181] The power loss caused by foreign matter can be defined as the power (P transmitted ) minus the actual power (P) received by the wireless power receiving device received ) is obtained. Because the wireless power transmission device already knows the power it transmits (P transmitted ), so once the wireless power transmitting device knows the actual power (P received ), the power loss can be calculated. To this end, the wireless power receiving device can periodically send a received power data packet (RP) to the wireless power transmitting device to transmit the power (P received )Notify the wireless power transmission device.

[0182] Meanwhile, although the wireless power transmission device and the wireless power receiving device are composed of various circuit elements inside and constitute independent devices, since these devices perform wireless power transmission through magnetic coupling between them, they constitute a wireless power transmission system. The power transmission characteristic uniquely determines the amount of power transmitted by the wireless power transmission device (transmitted power) and the amount of power received by the wireless power receiving device (received power). For example, the power transmission characteristic can be described by a ratio or function of the transmitted power and the received power. Therefore, the wireless power transmission device knows the power transmission characteristic in advance, and the amount of power received by the wireless power receiving device can be predicted based on the wireless power transmitted by the wireless power transmission device. Assume that the actual received power reported by the wireless power receiving device is less than the received power predicted based on the power transmission characteristic; in this case, it can be considered that power loss has occurred during the power transmission process. The foreign matter detection method based on power loss can determine that a foreign matter exists in this case. In this case, the foreign matter detection method based on power loss can determine that a foreign matter exists. In this way, since the power loss used to detect foreign matter is also determined based on the power transmission characteristic, it is necessary to correctly understand the power transmission characteristic to increase the reliability of foreign matter detection.

[0183] The power transfer characteristics depend on the inherent factors of the environment or device in which the wireless power is transmitted. The wireless power transmission and reception devices can generally use power calibration at the beginning of wireless power transmission to grasp the power transfer characteristics in any given wireless charging environment. When the power transfer characteristics are identified or configured through power calibration, foreign object detection can be performed accordingly.

[0184] The power transfer characteristics may also depend on changes in the load or changes in the magnetic coupling strength. For example, when the wireless power receiving device adopts multiple load steps or a changing load (or an increased load) or when the magnetic coupling strength changes due to a change in the position of the wireless power transmitting and receiving devices, at least part of the power transfer characteristics may change. When at least part of the power transfer characteristics changes, at least part of the power calibration parameters configured according to the previous power transfer characteristics become invalid. In addition, power loss and foreign object detection performed according to at least part of the configured power calibration parameters are no longer valid. Therefore, additional power calibration applicable to the changed power transfer characteristics is required.

[0185] When a foreign object is detected due to power loss, the accuracy of the received power value that the wireless power receiving device periodically transmits through the received power packet is essential; the WPC Qi specification requires high accuracy as shown in Table 3.

[0186] [Table 3]

[0187] Estimated received power <![CDATA[ΔP r ]]> unit <![CDATA[Pr (est) ≤5W]]> 350 mW <![CDATA[5W<Pr (est) ≤10W]]> 500 mW <![CDATA[10W<Pr (est) ]]> 750 mW

[0188] Referring to Table 3, when the wireless power receiving device receives wireless power greater than 5 W, the resolution of the received power value required by the wireless power receiving device is greater than 500 mW. Therefore, there arises a problem that foreign matter consuming less than 500 mW of power cannot be detected with the above-mentioned resolution.

[0189] In order to compensate for the accuracy of the received power value during transmission and reception of wireless power greater than 5 W, a two-point power calibration method is used.

[0190] Fig.10 is a state diagram illustrating a two-point power calibration method, and Fig.11 is a graph illustrating a power calibration curve according to a two-point power calibration method.

[0191] refer to Fig.10 , after completing the negotiation phase, the wireless power receiving device sends a first receiving power packet (RP / 1) and a second receiving power packet (RP / 2) at the beginning of the power transmission step to allow the wireless power transmitting device to construct a two-point power calibration curve.

[0192] More specifically, the wireless power receiving device transmits a first reception power packet (RP / 1) including information on a first calibration data point to the wireless power transmitting device SR1.

[0193] The first received power packet (RP / 1) includes a mode field and an estimated received power value field (see Fig.13 ). The wireless power transmitting device can confirm that the received power packet (RP) received from the wireless power receiving device is the first received power packet (RP / 1) including information about the first calibration data point through the value of the mode field of the first received power packet (RP / 1), and confirm the first calibration data point through the value of the estimated received power value field of the first received power packet (RP / 1).

[0194] The first calibration data point is the starting point of the power calibration curve and may be a power level corresponding to approximately 10% of the reference power level of the power transfer contract established in the negotiation phase, and may be a received power value received by the wireless power receiving device under a light load condition. The light load condition may indicate a situation where a load (e.g., a battery) is not electrically connected to the wireless power receiving device.

[0195] At the same time, the wireless power receiving device sends a control error (CE) packet to the wireless power transmitting device, wherein the CE packet includes a control error value. The control error value includes information about the deviation between the target operating point and the actual operating point of the wireless power receiving device. For example, when the CE value is positive, it indicates that the actual operating point is lower than the target operating point, and the wireless power transmitting device receiving the CE value increases the power of the transmitted wireless power. On the other hand, if the CE value is negative, it indicates that the actual operating point is higher than the target operating point, and the wireless power transmitting device receiving the CE value reduces the power of the transmitted wireless power.

[0196] The wireless power transmission device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with ACK or NAK in response to the first received power data packet (RP / 1) ST1. More specifically, the wireless power transmission device determines whether the power level is stable at the first calibration data point based on the control error value. For example, when the control error value is less than 3, the wireless power transmission device can determine that the power level is stable and the wireless power receiving device has reached the desired target operating point; and responds with ACK in response to the first received power packet (RP / 1). When the control error value is greater than 3, the wireless power transmission device can determine that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and responds with NAK in response to the first received power packet (RP / 1).

[0197] The wireless power receiving device continues to send the first reception power packet (RP / 1) until it receives ACK SR1 from the wireless power transmitting device. In addition, in order to stabilize the power level at the first calibration data point, the wireless power receiving device also repeatedly sends a control error packet to the wireless power transmitting device.

[0198] After the power level stabilizes at the first calibration data point and an ACK is received from the wireless power transmission device in response to the first receive power packet (RP / 1), the wireless power reception device sends a second receive power packet (RP / 2) including information about the second calibration data point to the wireless power transmission device SR2.

[0199] The second received power packet (RP / 2) also includes a mode field and an estimated received power value field (see Fig.13 ). The wireless power transmitting device can confirm that the received power packet (RP) received from the wireless power receiving device is the second received power packet (RP / 2) including information about the second calibration data point through the value of the mode field of the second received power packet (RP / 2), and confirm the second calibration data point through the value of the estimated received power value field of the second received power packet (RP / 2).

[0200] The second calibration data point may be used to construct a power calibration curve corresponding to a power level close to a reference power level of the power transfer contract established in the negotiation phase and indicating a received power value received by the wireless power receiving device under a connected load condition. The connected load condition may indicate a situation where a load is connected to the wireless power receiving device.

[0201] The wireless power transmission device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet and responds with ACK or NAK in response to the second received power packet (RP / 2) ST2. More specifically, the wireless power transmission device determines whether the power level is stable at the second calibration data point based on the control error value. For example, when the control error value is less than 3, the wireless power transmission device can determine that the power level is stable and the wireless power receiving device has reached the desired target operating point; and responds with ACK in response to the second received power packet (RP / 2). When the control error value is greater than 3, the wireless power transmission device can determine that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and responds with NAK in response to the second received power packet (RP / 2).

[0202] The wireless power receiving device continues to send the second reception power packet (RP / 2) until it receives ACK SR2 from the wireless power transmitting device. In addition, in order to stabilize the power level at the second calibration data point, the wireless power receiving device also repeatedly sends a control error packet to the wireless power transmitting device.

[0203] After the power level stabilizes at the second calibration data point and an ACK is received from the wireless power transmission device in response to the second received power packet (RP / 2) SR3, the wireless power receiving device and the wireless power transmission device enter a normal power transmission mode. The wireless power transmission device can construct a power calibration curve based on the first received power packet (RP / 1) and the second received power packet (RP / 2) in response to which the ACK is sent, and check the occurrence of power loss due to foreign matter during power transmission based on the power calibration curve.

[0204] More specifically, the wireless power transmitting device can receive a received power packet (e.g., RP / 0) from the wireless power receiving device during power transmission, confirm the received power value received by the wireless power receiving device through the received power packet, and if the difference between the received power value calculated by applying the transmitted power value to the power calibration curve and the received power value confirmed by the ratio of the received power packet is greater than a threshold value, it is assumed that power loss has occurred due to foreign matter.

[0205] In the following, reference Fig.11, a power calibration curve according to the two-point power calibration method will be described.

[0206] The wireless power transmission device constructs a power calibration curve based on the first reception power packet (RP / 1) and the second reception power packet (RP / 2) in response to which ACK is transmitted.

[0207] Assume that the predicted value of the transmission power is given by P t(est) Indicates that the predicted value of the received power is obtained by P r(est) Indicates that the actual transmit power value is expressed by P t The actual received power value is expressed by P r Indicates; if it is confirmed by foreign object detection (FOD) (pre-power FOD) before power transmission that there is no foreign object between the wireless power transmitting device and the wireless power receiving device, the following equation 1 is satisfied.

[0208] [Equation 1]

[0209] Pt(est)+δPt=Pt=Pr=Pr(est)-δPr

[0210] In Equation 1, δP t δP is the prediction error value of the transmission power and may include the power loss inherent to the wireless power transmission device. r is a prediction error value of the received power and may include power loss inherent to the wireless power receiving device.

[0211] Based on Equation 1, the calibrated power value P (cal) It can be calculated by the following equation 2.

[0212] [Equation 2]

[0213] P(cal)=δPt+δPr=Pr(est)-Pt(est)

[0214] Therefore, if RP / 1 (the first calibration data point) and RP / 2 (the second calibration data point) are inserted into Equation 2, the calibrated power values ​​can be expressed using Equation 3, respectively.

[0215] [Equation 3]

[0216] P1(cal)=RP / 1-Pt1(est)

[0217] P2(cal)=RP / 2-Pt2(est)

[0218] In other words, if it is confirmed from the pre-power FOD that there is no foreign matter, the relationship described by equations 1 to 3 is established, and the calibration curve based on equations 1 to 3 can be as follows: Fig.11 Build as shown in .

[0219] The calibration protocol using two points (RP / 1 and RP / 2) cannot support the situation where the wireless power receiving device reaches the final load power through multiple steps. Therefore, a multi-point based power calibration method is needed.

[0220] According to WPC Qi version 1.2.4, calibration information (RP / 1 and RP / 2) is only allowed to be transmitted once before starting power transfer; therefore, when the wireless power receiving device changes the operating point (e.g., target rectified voltage) during power transfer, the wireless power transmitting device cannot generate a new calibration curve during power transfer.

[0221] According to WPC Qi version 1.2.4, when power recalibration is required, the wireless power receiving device must reset the wireless power transmitting device by sending an EPT / rep packet and restart the protocol for wireless power transmission from the beginning. Therefore, there is a problem that the wireless power receiving device has to stop receiving power to recalibrate the power. Therefore, during power transmission, a multi-point based power recalibration method is required.

[0222] In addition, when the wireless power receiving device sends a second receiving power packet (RP / 2), the RP / 2 power level (second calibration data point) may be limited depending on the battery charge state. In particular, when the battery is almost fully charged, the difference between RP / 1 (first calibration data point) and RP / 2 (second calibration data point) becomes smaller, so that the power calibration range is limited. In addition, when high power transmission is required due to the reduction of battery charge due to the operation of various applications during power transmission, because the calibration power itself is outside the range of the initial calibration curve, there is a problem that the calibration curve must be extrapolated. Therefore, in order to prevent extrapolation, a method is needed to send additional calibration points to the wireless power transmitting device to extend the existing calibration curve while maintaining the operating point (e.g., target rectified voltage) during charging. In other words, a multi-point calibration method is required to use multiple points to extend the calibration curve.

[0223] Hereinafter, a multi-point power calibration method of an extended power calibration curve will be described.

[0224] Fig.12 is a flowchart illustrating a multi-point power calibration method according to one embodiment, Fig.13 FIG. 1 illustrates a format of a received power packet according to one embodiment, Fig.14 is a state diagram illustrating a multi-point power calibration method using multiple RP / 2 according to one embodiment, Fig.15 is a graph illustrating a power calibration curve according to a multi-point power calibration method using multiple RP / 2 according to one embodiment, and Fig.16is a graph illustrating a power calibration curve according to a multi-point power calibration method using a plurality of RP / 2 according to another embodiment.

[0225] refer to Fig.12 According to the multi-point power calibration protocol of the extended power calibration curve, the wireless power receiving device sends a CE packet to the wireless power transmitting device S1101. Since the CE packet has been described above, its detailed description will be omitted.

[0226] refer to Fig.12 and Fig.14 , the wireless power receiving device sends a first receiving power packet (RP / 1) including information about the first calibration data point to the wireless power transmitting device S1102, SR1. The CE packet and the first receiving power packet (RP / 1) are sent after the negotiation phase, which can be sent at the beginning of the power transmission phase or before the power transmission phase.

[0227] refer to Fig.13 , the first received power packet (RP / 1) includes a mode field and an estimated received power value field. The wireless power transmitting device can confirm that the received power packet (RP) received from the wireless power receiving device is the first received power packet (RP / 1) including information about the first calibration data point through the value of the mode field of the first received power packet (RP / 1), and confirm the first calibration data point through the value of the estimated received power value field of the first received power packet (RP / 1).

[0228] The first calibration data point is the starting point of the power calibration curve and may be a power level corresponding to approximately 10% of the reference power level of the power transfer contract established in the negotiation phase and may be a received power value received by the wireless power receiving device under a light load condition. The light load condition may indicate a situation where a load (e.g., a battery) is not electrically connected to the wireless power receiving device.

[0229] The wireless power transmission device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with ACK or NAK in response to the first received power packet (RP / 1) ST1. More specifically, when the control error value is less than or equal to a predetermined level, the wireless power transmission device determines that the power level is stable and the wireless power receiving device has reached the desired target operating point, and responds with ACK in response to the first received power packet (RP / 1) S1103. When the control error value is greater than or equal to a predetermined level, the wireless power transmission device determines that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and can respond with NAK in response to the first received power packet (RP / 1).

[0230] The wireless power receiving device continues to send the first reception power packet (RP / 1) until it receives ACK from the wireless power transmitting device S1102. In addition, in order to stabilize the power level of the first calibration data point, the wireless power receiving device also repeatedly sends a control error packet to the wireless power transmitting device S1101.

[0231] After receiving ACK from the wireless power transmission device in response to the first reception power packet (RP / 1), the wireless power reception device transmits a second reception power packet (RP / 2) including information about the second calibration data point to the wireless power transmission device S1105, SR2.

[0232] refer to Fig.13 The second receiving power packet (RP / 2) also includes a mode field and an estimated receiving power value field (see Fig.13 ). The wireless power transmitting device can confirm that the received power packet (RP) received from the wireless power receiving device is the second received power packet (RP / 2) including information about the second calibration data point by the value of the mode field of the second received power packet (RP / 2), and confirm the second calibration data point by the value of the estimated received power value field of the second received power packet (RP / 2). In order for the wireless power transmitting device to distinguish between the first calibration data point and the second calibration data point, the mode field of the first received power packet (RP / 1) and the mode field of the second received power packet (RP / 2) have different values. For example, the mode field of the first received power packet (RP / 1) may have a value of 1 ("001"b), and the mode field of the second received power packet (RP / 2) may have a value of 2 ("010"b).

[0233] The second calibration data point may be used to construct a power calibration curve corresponding to a power level close to a reference power level of the power transfer contract established in the negotiation phase and indicating a received power value by the wireless power receiving device under a connected load condition. The connected load condition may indicate a situation where a load is connected to the wireless power receiving device.

[0234] At the same time, the wireless power receiving device sends a CE packet to the wireless power transmitting device S1104. The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with ACK or NAK in response to the second received power packet (RP / 2) ST2. When the control error value is less than or equal to a predetermined level, the wireless power transmitting device determines that the power level is stable and the wireless power receiving device has reached the desired target operating point, and responds with ACK in response to the second received power packet (RP / 2) S1106. When the control error value is greater than or equal to a predetermined level, the wireless power transmitting device determines that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and may respond with NAK in response to the second received power packet (RP / 2).

[0235] The wireless power receiving device continues to send the second receiving power packet (RP / 2) until it receives ACK from the wireless power transmitting device (S1105). In addition, in order to stabilize the power level of the second calibration data point, the wireless power receiving device also repeatedly sends the control error packet S1104 to the wireless power transmitting device.

[0236] After receiving the ACK in response to the second receive power packet (RP / 2), the wireless power receiving device may determine whether it is necessary to send a continuous calibration data point. For example, the wireless power receiving device may check whether the desired target load power has been reached, or whether the operating point (e.g., V rec (rectified voltage)) while whether a new calibration data point outside the range between the first calibration data point and the second calibration data point is needed. In other words, when the target load power has not yet been reached, the wireless power receiving device can check whether it is necessary to gradually increase to the target load power and whether a new calibration data point outside the range between the first calibration data point and the second calibration data point is needed, taking into account changes in the use environment of the battery being charged.

[0237] When there is no need to transmit continuous calibration points, the wireless power receiving device may send a receive power packet (RP / 0 or RP / 4) whose mode field has a value different from the value of the mode field of the first receive power packet (RP / 1) and the second receive power packet (RP / 2), so that the power calibration protocol can be terminated and normal power transmission can resume SR3. The wireless power receiving device may send RP / 0 or RP / 4 to avoid calibration timeout, so that the power calibration protocol can be terminated. Reference Fig.13, RP / 0 or RP / 4 may also have the same format as the first reception power packet (RP / 1) and the second reception power packet (RP / 2), and include an estimated reception power value indicating a normal value. Because RP / 0 or RP / 4 has a mode field whose value is different from the value of the mode field of the first reception power packet (RP / 1) and the second reception power packet (RP / 2), the wireless power transmission device can distinguish RP 0 or RP / 4 from RP / 1 and RP / 2.

[0238] When it is necessary to transmit consecutive calibration points, the wireless power receiving device can use the second receiving power packet (RP / 2) again to send the third calibration point (one of the consecutive calibration points) to the wireless power transmitting device. In other words, the wireless power receiving device sends a new second receiving power packet (RP / 2) including information about the third calibration point to the wireless power transmitting device S1108, SR3.

[0239] The third calibration data point is used to construct the power calibration curve and may be a power value higher than the second calibration data point to which the wireless power transmission device has responded with ACK or a power value lower than the first calibration data point to which the wireless power transmission device has responded with ACK.

[0240] At the same time, the wireless power receiving device sends the CE packet to the wireless power transmitting device S1107. The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds by ACK or NACK in response to the new second received power packet (RP / 2) ST2. When the control error value is less than or equal to the preset level, the wireless power transmitting device determines that the power level is stable and the wireless power receiving device has reached the desired target operating point; and responds with ACK in response to the new second received power packet (RP / 2) S1109. When the control error value is greater than or equal to the predetermined level, the wireless power transmitting device determines that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and can respond by NAK in response to the new second received power packet (RP / 2).

[0241] The wireless power receiving device continues to send new second reception power packets (RP / 2) until it receives ACK from the wireless power transmitting device S1108. In addition, in order to stabilize the power level at the third calibration data point, the wireless power receiving device also repeatedly sends control error packets to the wireless power transmitting device S1107.

[0242] refer to Fig.15The wireless power transmission device constructs a power calibration curve based on the calibration data points respectively included in the first reception power packet (RP / 1), the second reception power packet (RP / 2) and the new second reception power packet (RP / 2) in response to which ACK is sent.

[0243] When constructing a power calibration curve based on three calibration data points, a first power calibration curve A1 connecting the first calibration data point (Pt1, RP / 1) and the second calibration data point (Pt2, RP / 2) and a second power calibration curve A2 connecting the second calibration data point (Pt2, RP / 2) and the third calibration data point (Pt3, RP / 2) can be constructed.

[0244] The first power calibration curve A1 and the second power calibration curve A2 can be defined as first-order functions with different slopes and y-intercepts, and the wireless power transmitting device uses the received power value confirmed by using the received power packet received from the wireless power receiving device, the transmitted power value, and the power calibration curve including the first power calibration curve A1 and the second power calibration curve A2 to perform foreign object detection S1110 due to the loss of transmission power.

[0245] At the same time, depending on the need, the wireless power receiving device can enable the wireless power transmitting device to extend the power calibration curve by sending a fourth calibration data point to the wireless power transmitting device. In this case, the wireless power receiving device can send the fourth calibration point as one of the continuous calibration points to the wireless power transmitting device by using the second receiving power packet (RP / 2) again.

[0246] The wireless power receiving device transmits a new second receiving power packet (RP / 2) including information about the fourth calibration point to the wireless power transmitting device; the wireless power transmitting device transmits ACK or NAK based on the control error value included in the control error packet. Since the detailed description of the above operation is similar to the description of transmitting the second receiving power packet (RP / 2) including information about the third calibration point, its detailed description will be omitted.

[0247] refer to Fig.16 , when constructing a power calibration curve based on the four calibration data points included in the received power group in response to which ACK is sent, the wireless power transmission device can construct a first power calibration curve A1 connecting the first calibration data point (Pt1, RP / 1) and the second calibration data point (Pt2, RP / 2), a second power calibration curve A2 connecting the second calibration data point (Pt2, RP / 2) and the third calibration data point (Pt3, RP / 2), and a third power calibration curve A3 connecting the third calibration data point (Pt3, RP / 2) and the fourth calibration data point (Pt4, RP / 2); and perform foreign object detection using the constructed power calibration curve.

[0248] In a similar manner, the wireless power receiving device and the wireless power transmitting device may construct a multi-point power calibration curve using one first reception power group (RP / 1) and a plurality of second reception power groups (RP / 2).

[0249] Also, a calibration timeout can be configured for the power calibration protocol. This is intended to prevent the insertion of foreign objects while the power calibration protocol is in progress.

[0250] The calibration timeout may include a calibration timeout (PRx calibration timeout) of the wireless power receiving device and a calibration timeout (PTx calibration timeout) of the wireless power transmitting device.

[0251] The calibration timeout of the wireless power receiving device refers to the time during which the wireless power receiving device performs power calibration, for example, it can be defined as the time required to send RP / 0 or RP / 4 after transmitting the first RP / 1. For example, the calibration timeout of the wireless power receiving device can be configured to 16 seconds.

[0252] The calibration timeout of the wireless power transmission device can be defined as the time required for the wireless power transmission device to send the first ACK in response to RP / 2 after receiving the first RP / 1. The calibration timeout of the wireless power transmission device can be less than the calibration timeout of the wireless power reception device, for example, it can be configured to 10 seconds.

[0253] Fig.17 is a state diagram illustrating a multi-point power calibration method using RP / 3 according to one embodiment, and Fig.18 is a graph illustrating a power calibration curve according to a multi-point power calibration method using RP / 3 according to one embodiment.

[0254] refer to Fig.17 , steps S1201 to S1206 of the multi-point power calibration protocol using the RP / 3 extended power calibration curve are the same as Fig.12 Therefore, detailed description thereof will be omitted.

[0255] However, with reference Figures 12 to 16 Unlike the described embodiments, when continuous calibration points need to be transmitted, the wireless power receiving device according to this embodiment sends the third calibration point as one of the continuous calibration points by using the third receiving power group (RP / 3) instead of the second receiving power group (RP / 2).

[0256] The third received power packet (RP / 3) may have the same format as the first received power packet (RP / 1) and the second received power packet (RP / 2) (see Fig.13). However, the mode field of the third reception power packet (RP / 3) may have a value different from the mode field values ​​of the first reception power packet (RP / 1) and the second reception power packet (RP / 2). For example, the mode field of the first reception power packet (RP / 1) may have a value of 1 ("001"b), the mode field of the second reception power packet (RP / 2) may have a value of 2 ("010"b), and the mode field of the third reception packet (RP / 3) may have a value of 3 ("011"b).

[0257] In other words, after step S1206, when it is necessary to transmit consecutive calibration points, the wireless power receiving device transmits a third reception power packet (RP / 3) including information on a third calibration point to the wireless power transmitting device S1208.

[0258] At the same time, the wireless power receiving device sends a CE packet to the wireless power transmitting device S1207. The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with ACK or NAK in response to the third received power packet (RP / 3). When the control error value is less than or equal to the preset level, the wireless power transmitting device determines that the power level is stable and the wireless power receiving device has reached the desired target operating point; and responds with ACK in response to the third received power packet (RP / 3) S1209. When the control error value is greater than or equal to the predetermined level, the wireless power transmitting device determines that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and may respond with NAK in response to the third received power packet (RP / 3).

[0259] The wireless power receiving device continues to send the third receiving power packet (RP / 3) until it receives ACK from the wireless power transmitting device (S1208). In addition, in order to stabilize the power level of the third calibration data point, the wireless power receiving device also repeatedly sends the control error packet S1207 to the wireless power transmitting device.

[0260] refer to Fig.18 The wireless power transmission device constructs a power calibration curve based on the calibration data points respectively included in the first reception power group (RP / 1), the second reception power group (RP / 2) and the third reception power group (RP / 3) in response to which ACK is sent.

[0261] When constructing a power calibration curve based on three calibration data points, the wireless power transmitting device can construct a first power calibration curve B1 connecting the first calibration data point (Ptl, RP / 1) and the second calibration data point (Pt2, RP / 2), and a second power calibration curve B2 connecting the second calibration data point (Pt2, RP / 2) and the third calibration data point (Pt3, RP / 3).

[0262] The first power calibration curve B1 and the second power calibration curve B2 can be defined as first-order functions with different slopes and y-intercepts, and the wireless power transmitting device uses the received power value confirmed by using the received power packet received from the wireless power receiving device, the transmitted power value, and the power calibration curve including the first power calibration curve B1 and the second power calibration curve B2 to perform foreign object detection due to transmission power loss, S1210.

[0263] As described above, because the power calibration curve can be extended, the calibration range is increased so that a wider range of power values ​​can be calibrated, and because the calibration reliability is improved, the reliability of foreign object detection based on power loss is also increased.

[0264] Hereinafter, a multi-point power calibration method for recalibrating a power calibration curve will be described.

[0265] Fig.19 is a flow chart illustrating a power recalibration method according to one embodiment, Fig. 20 is a state diagram illustrating a power recalibration method according to one embodiment, and Fig.21 is a graph illustrating a power calibration curve according to a power recalibration method according to another embodiment.

[0266] The power recalibration protocol according to one embodiment can be distinguished by an initial calibration protocol and a subsequent calibration protocol. Fig.19 , the initial calibration protocol includes steps S1301 to S1306, and the subsequent calibration protocol includes steps S1310 to S1315.

[0267] Steps S1301 to S1306 of the initial calibration protocol are similar to Fig.12 Therefore, the detailed description thereof will be omitted.

[0268] Although Fig.19 The initial calibration protocol shown in uses a two-point calibration protocol to construct a power calibration curve based on two calibration data points. The initial calibration protocol can use a reference Figures 12 to 18 A multi-point calibration protocol for constructing a power calibration curve based on three or more calibration data points is described.

[0269] Assume that because there is no need to transmit consecutive calibration points anymore after receiving an ACK in response to a second receive power packet (RP / 2) including information about a second calibration data point sent by the wireless power receiving device, RP / 0 or RP / 4 is sent to terminate the initial calibration protocol; in this case, the initial calibration protocol is performed using a two-point calibration protocol.

[0270] At the same time, when continuous transmission of calibration points is required after receiving an ACK in response to a second receive power packet (RP / 2) including information about a second calibration data point sent by the wireless power receiving device, thereby sending a second or third receive power packet including information about a third calibration data point, the initial calibration protocol is performed based on a multi-point calibration protocol.

[0271] If the initial calibration protocol is completed, the wireless power transmission device constructs a power calibration curve according to the initial calibration protocol and performs foreign object detection based on the power calibration curve S1307.

[0272] When it is determined that there is no foreign matter according to the result of the foreign matter detection, the power transmission stage is performed, and the wireless power transmission device transmits wireless power to the wireless power reception device S1308. For the convenience of description, Fig.19 The diagram shows a situation where the power transfer phase is performed after step S1307; however, the initial calibration protocol may be performed starting from the power transfer phase.

[0273] When the wireless power receiving device changes the target operating point (e.g., target rectified voltage) in the middle of wireless power transmission (S1309), a subsequent calibration protocol is performed, and the wireless power receiving device sends a new first received power packet (RP / 1) to the wireless power transmitting device, which includes information about the new first calibration data point (S1311, SR4→SR1). Fig.21 , for example, the wireless power receiving device may change the target operating point from a first operating point (5 V) to a second operating point (12 V).

[0274] The new first received power packet (RP / 1) also has the same format as the other received power packets. The new first received power packet (RP / 1) has the same mode field value as the first received power packet (RP / 1) sent in step S1302. However, because the new first received power packet (RP / 1) includes information about calibration data points that is different from the information included in the first received power packet (RP / 1) sent in step S1302, the value of the estimated received power value field may be different from the field of the first received power packet (RP / 1) sent in step S1302.

[0275] The wireless power transmission device can confirm that the received power packet (RP) received from the wireless power reception device is a new first received power packet (RP / 1) including information about a new first calibration data point through the value of the mode field of the new first received power packet (RP / 1), and can confirm the new first calibration data point through the value of the estimated received power value field of the new first received power packet (RP / 1). The new first calibration data point becomes the starting point of the power calibration curve updated by the recalibration protocol.

[0276] At the same time, the wireless power receiving device sends the CE packet to the wireless power transmitting device S1310. The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds to the new second received power packet (RP / 2) by ACK or NAK ST2. Because detailed descriptions related to the above have been given, they will be omitted.

[0277] The wireless power receiving device continues to send new first reception power packets (RP / 1) and control error packets S1310 , S1311 until it receives an ACK from the wireless power transmitting device S1312 .

[0278] After receiving ACK from the wireless power transmitting device in response to the new first receiving power packet (RP / 1), the wireless power receiving device sends a new second receiving power packet (RP / 2) including information about the new second calibration data point to the wireless power transmitting device S1314, SR2.

[0279] The new second received power packet (RP / 2) also has the same format as the other received power packets. The new second received power packet (RP / 2) has the same mode field value as the second received power packet (RP / 2) sent in step S1305. However, because the new second received power packet (RP / 2) includes information about calibration data points that is different from the information included in the second received power packet (RP / 2) sent in step S1305, the value of the estimated received power value field may be different from the value of the second received power packet (RP / 2) sent in step S1305.

[0280] The wireless power transmission device can confirm that the received power packet (RP) received from the wireless power reception device is a new second received power packet (RP / 2) including information about the new second calibration data point through the value of the mode field of the new second received power packet (RP / 2), and can confirm the new second calibration data point through the value of the estimated received power value field of the new second received power packet (RP / 2). The new second calibration data point constitutes a point for constructing a power calibration curve updated by the recalibration protocol.

[0281] At the same time, the wireless power receiving device sends the CE packet to the wireless power transmitting device S1313. The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with ACK or NACK in response to the new second received power packet (RP / 2) ST2. Since detailed descriptions related to the above have been given, they will be omitted.

[0282] The wireless power receiving device continues to send new second reception power packets (RP / 2) and control error packets S1313, S1314 until it receives an ACK from the wireless power transmitting device, S1315.

[0283] After receiving an ACK in response to the new second receive power packet (RP / 2), the wireless power receiving device may determine whether it is necessary to send consecutive calibration data points.

[0284] When there is no need to transmit continuous calibration points, the wireless power receiving device can send a receive power packet (RP / 0 or RP / 4) whose mode field has a value different from the value of the first receive power packet (RP / 1) and the second receive power packet (RP / 2), so that the power calibration protocol can be terminated and normal power transmission SR3 can be resumed.

[0285] The wireless power transmission device updates the power calibration curve based on the new first and second calibration points received through the subsequent calibration protocol, and performs foreign object detection using the updated power calibration curve S1316.

[0286] Although for ease of description Fig.19 The following calibration protocol is also performed based on the two-point calibration protocol. When the wireless power receiving device sends a second or third received power packet including information about a third calibration data point because continuous calibration points need to be transmitted after step S1315, the following calibration protocol is performed based on the multi-point calibration protocol. In this case, the wireless power transmitting device uses the power calibration curve updated according to the multi-point calibration protocol to perform foreign object detection S1316.

[0287] refer to Fig.21 , with the initial calibration protocol based on the reference Fig.12 The described multi-point calibration protocol using one RP / 1 and multiple RP / 2 is performed at the first operating point (5V), and the initial calibration curve is constructed accordingly. Afterwards, the operating point is changed to the second operating point (12V), and as the subsequent calibration protocol is also performed at the second operating point based on the multi-point calibration protocol using one RP / 1 and multiple RP / 2, the power calibration curve is also updated accordingly.

[0288] According to the power recalibration method, when the wireless power receiving device changes an operating point (eg, a target rectified voltage) during power transmission, power recalibration may be performed without resetting the wireless power transmitting device.

[0289] Therefore, by resetting the wireless power transmission device, the charging time of the wireless power reception device can be prevented from being extended, and because the power calibration curve can be updated due to the change of the operating point, the reliability of foreign matter detection is also increased.

[0290] In the above, the multi-point power calibration method of extending the power calibration curve and the multi-point power calibration method of recalibrating the power calibration curve have been described. The power calibration method combining the multi-point power calibration method of extending the power calibration curve and the multi-point power calibration method of recalibrating the power calibration curve will be described below.

[0291] Fig. 22 is a flow chart illustrating a power calibration method according to one embodiment.

[0292] refer to Fig. 22 The wireless power transmitting device and the wireless power receiving device go through the ping phase S1401, the configuration phase S1402, and the negotiation phase S1403; and continue the calibration protocol. The wireless power receiving device sends the first calibration data point and the second calibration data point to the wireless power transmitting device by sending the first receiving power packet (RP / 1) and the second receiving power packet (RP / 2) S1404.

[0293] The wireless power transmission device constructs a calibration curve using the first and second calibration data points of the first reception power packet (RP / 1) and the second reception power packet (RP / 2) in response to which ACK is sent; transmits wireless power based on the calibration curve S1405; and performs foreign object detection.

[0294] Thereafter, as the wireless power receiving device changes the target operating point (eg, target rectified voltage), a multi-point power calibration method that extends the power calibration curve or a multi-point power calibration method that recalibrates (or updates) the power calibration curve is used for further progress.

[0295] When the wireless power receiving device does not change the target operating point S1406 and it is necessary to send continuous calibration points, the multi-point power calibration method of the extended power calibration curve is used to further progress S1407. As described above, the multi-point power calibration method of the extended power calibration curve uses a new second received power packet (RP / 2) or a third received power packet (RP / 3) to send a third calibration data point to the wireless power transmitting device. The wireless power transmitting device uses the first and second calibration data points received in step S1404 and the third calibration data point received in step S1407 to construct a power calibration curve.

[0296] At the same time, when the wireless power receiving device changes the target operating point S1406, a multi-point power calibration method for recalibrating (or updating) the power calibration curve is used. As described above, the multi-point power calibration method for recalibrating (or updating) the power calibration curve uses a new first received power group (RP / 1) and a new second received power group (RP / 2) to send new first and second calibration time points to the wireless power transmitting device. The wireless power transmitting device recalibrates (or updates) the power calibration curve using the newly received first and second calibration data points.

[0297] In other words, the wireless power receiving device and the wireless power transmitting device perform a calibration protocol that extends an existing power calibration curve or a calibration protocol that updates an existing power calibration curve depending on whether a target operating point is changed.

[0298] according to Figures 10 to 22 The wireless power transmission device of the embodiment corresponds to Figures 1 to 9 Therefore, the operation of the wireless power transmission device according to this embodiment is achieved by combining Figures 1 to 9 For example, the communication / control unit 120 may perform reception of data packets for detecting foreign objects by the wireless power transmission device, construction, expansion and / or update of a power calibration curve, execution of a foreign object detection method, transmission of ACK / NAK due to a result of foreign object detection, and the like.

[0299] In addition, according to Figures 10 to 22 The wireless power receiving device of the embodiment corresponds to Figures 1 to 9 Therefore, the operation of the wireless power receiving device according to this embodiment is achieved by combining Figures 1 to 9 For example, the communication / control unit 220 may perform transmission of a data packet for detecting foreign matter by the wireless power receiving device, reception of ACK / NAK due to the result of foreign matter detection, and the like.

[0300] In the wireless power transmission method and device or receiving device and method according to an embodiment of the present invention, since all components or steps are not necessary, the wireless power transmission device and method or the receiving device and method can be performed by including some or all of the components or steps of the above components or steps. In addition, the embodiments of the wireless power transmission device and method or the receiving device and method can be performed in combination. In addition, it is not necessary that the above components or steps should be performed in the above order, and the steps described later can be performed before the steps described earlier.

[0301] The foregoing description merely provides the technical concept of the present invention, and those skilled in the art may make various changes and modifications without departing from the essential features of the present invention. Therefore, the foregoing embodiments of the present invention may be implemented individually or in combination.

[0302] Therefore, the embodiments disclosed in the present invention are used to illustrate rather than limit the scope of the present invention, and the concept of the technical idea of ​​the present invention is not limited by these embodiments. The protection scope of the present invention should be understood according to the following claims, and all technical ideas in the equivalent scope of the claims should be understood to fall within the scope of the present invention.

Claims

1. A wireless power transmitter for transmitting wireless power to a wireless power receiver, the wireless power transmitter being configured to: After the negotiation phase, receiving a first receive power packet from the wireless power receiver, the first receive power packet including an estimated receive power value for a first calibration data point; sending an ACK in response to the first received power packet; receiving a second receive power packet from the wireless power receiver, the second receive power packet including an estimated receive power value for a second calibration data point; sending an ACK in response to the second received power packet; receiving a new second receive power packet from the wireless power receiver, the new second receive power packet including an estimated receive power value for a third calibration data point; sending an ACK in response to the new second received power packet; constructing a power calibration curve based on the first received power grouping, the second received power grouping and the new second received power grouping, and performing foreign object detection based on the power calibration curve, wherein the ACK in response to the first reception power packet, the second reception power packet, or the new second reception power packet is sent when the power level is stabilized based on the control error packet including the control error value.

2. The wireless power transmitter according to claim 1, in, The first received power packet, the second received power packet, and the new second received power packet have the same packet structure including a mode field; and The mode field of the first reception power packet has a different value from the mode fields of the second reception power packet and the new second reception power packet.

3. The wireless power transmitter according to claim 2, in, The mode field of the second reception power packet has the same value as the mode field of the new second reception power packet.

4. A wireless power receiver for receiving wireless power from a wireless power transmitter, the wireless power receiver being configured to: After the negotiation phase, sending a first receive power packet to the wireless power transmitter, the first receive power packet including an estimated receive power value for a first calibration data point; receiving an ACK in response to the first receive power packet from the wireless power transmitter; transmitting a second received power packet to the wireless power transmitter, the second received power packet including an estimated received power value for a second calibration data point; receiving an ACK in response to the second receive power packet from the wireless power transmitter; transmitting a new second received power packet to the wireless power transmitter, the new second received power packet including an estimated received power value for a third calibration data point; and receiving an ACK in response to the new second receive power packet from the wireless power transmitter, Wherein, when the power level is stabilized based on the control error packet including the control error value, the ACK is received in response to the first reception power packet, the second reception power packet, or the new second reception power packet. 5 . The wireless power receiver of claim 4 , continuing to transmit the first reception power packet until an ACK in response to the first reception power packet is received from the wireless power transmitter. 6 . The wireless power receiver of claim 4 , continuing to transmit the second reception power packet until an ACK in response to the second reception power packet is received from the wireless power transmitter. 7 . The wireless power receiver of claim 4 , continuing to transmit the new second reception power packet until an ACK in response to the new second reception power packet is received from the wireless power transmitter. 8 . The wireless power receiver of claim 4 , terminating the power calibration protocol by transmitting a reception power packet including an estimated reception power value for a normal value to the wireless power transmitter.

9. The wireless power receiver according to claim 4, in, The first reception power packet, the second reception power packet and the new second reception power packet have the same packet structure including a mode field; and The mode field of the first reception power packet has a value different from values ​​of the mode fields of the second reception power packet and the new second reception power packet.

10. The wireless power receiver according to claim 4, in, The mode field of the second reception power packet has the same value as the mode field of the new second reception power packet.

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